The present invention relates to systems and techniques for encoding key assignments for keyboards and other data input devices.
The most familiar type of data input device is the QWERTY keyboard, whose key arrangement was designed primarily by Charles Latham Sholes in the late 19th century. The original QWERTY keyboard features a single input key for each letter of the English alphabet and additional keys for numbers, symbols, and punctuation. With the rise of computer use, the QWERTY keyboard layout has been expanded to include numerous modern computer function keys and other useful controls. It is believed that the QWERTY scheme was deliberately laid out with keys in impractical positions in order to slow down skilled typists, presumably to prevent jamming of the mechanical typewriters for which it was designed. Some of the least commonly used letters in the English language (J and K) are placed on the home row, and some of the most commonly used letters (E, T, O, I, and N) are not. In practice, the QWERTY layout requires awkward pathways of finger movement to construct words and users often suffer from repetitive strain injuries (“RSI”) as a result of frequent and long-term use of these keyboards.
The Dvorak keyboard was designed by August Dvorak and William L. Dealey in the mid-1930's in an effort to maximize typing efficiency. The Dvorak keyboard places all vowels on the home row for the left hand and the most common consonants on the home row for the right hand, therefore allowing a user to type in more of a rhythm and minimizing the number of awkward patterns necessary to construct words. Although the Dvorak keyboard has become more accessible in recent years due to software applications that eliminate the need for specialized hardware, the Dvorak keyboard has never achieved a high level of commercial success, and the QWERTY layout has remained the dominant standard for word processing and other applications.
With the introduction of cellphones and other handheld computing devices that allow text messaging (and more recently, for email and other uses), new input systems have become popular. For cellphones, the E.161 scheme was used to allow access to all 26 letters of the alphabet using the numbers 2-9 of a standard 12-key telephone keypad. The multi-tap approach (pressing a key repeatedly to cycle through the letter options) has been refined to include predictive texting (such as T-9) and other features, but still remains a cumbersome method of typing messages.
More modern touch-screen devices have increased the number of options, including an on-screen QWERTY keyboard and other methods of inputting text (handwriting recognition, Swype, SlideID, Shapewriter, etc.) but many users still prefer the QWERTY keyboard and many modern phones and PDA's are manufactured to include a physical keyboard for use with the device. Such keyboards are usually designed to be actuated by the user's thumbs, and typing speeds rarely exceed 40 words per minute, even for proficient users. Furthermore, most of these methods normally require the user to visually monitor the input source, preventing users from “touch-typing” and entering text and other data while the eyes are focused on other things.
Chord keyboards are known in the art and include between five and twelve keys. Most chord keyboards are designed so that either individual keys or combinations of multiple keys (chords) can be used to generate the 26 letters of the English alphabet as well as numeric and punctuation characters and function keys.